Add basic file parsing

csim.c

@@ -62,6 +62,30 @@ int main(int argc, char* argv[])
 	/* End of argument parsing. */
 	printf("Arguments: %zd, %zd, %zd, %hd, %s\n", set_index_bits, lines, block_bits, VERBOSE, filename);
 
+	char buffer[20];
+	FILE* f = fopen(filename, "r");
+	if(!f)
+	{
+		printf("Invalid file name: %s", filename);
+		exit(-1);
+	}
+
+	while (fgets(buffer, 20, f))
+	{
+		if (buffer[0] == 'I')
+			continue;
+
+		char* end;
+		char op = buffer[1];
+		long address = strtol(buffer+3, &end, 16);
+		if (*end != ',' || !(op == 'S' || op == 'L' || op == 'M'))
+		{
+			printf("Invalid input file, last line:\n%s\n", buffer);
+			return -1;
+		}
+		printf("%c %ld\n", op, address);
+	}
+
 	printSummary(0, 0, 0);
 	return 0;
 }